1. Field of the Invention
The present invention relates to a network camera system and an illumination device thereof, and more specifically, to a network camera system for calculating a maximum illumination power to transmit to an illumination unit according to a practical operation power of a network camera and an electrical power received by an illumination device and an illumination device thereof.
2. Description of the Prior Art
With development of PoE (Power over Ethernet) technology, a network camera system could utilize only one network cable to obtain electrical power and establish network signal transmission between a control terminal (e.g. a video surveillance host) and a network camera simultaneously via a PoE switch coupled to an external power source. Accordingly, the aforesaid design could efficiently solve the prior art problem that the wiring design of the network camera system is complicated since the network camera needs to be connected to the external power source and the control terminal respectively. In practical application, the network camera system usually utilizes an internal or external light source for providing auxiliary light to capture clear images when the network camera is operated in a dark environment (e.g. indoor or in the night).
In the aforesaid design, the PoE switch could provide a network power to the network camera and the light source via the network cable. However, since the network power is distributed in a fixed proportion for the network camera and the light source, the electrical power transmitted to the light source still remains the same even if the practical operation power of the network camera is varied (e.g. the original network camera is replaced with another network camera with a lower operation power). In such a manner, the aforesaid design may cause a poor power utilization efficiency of the network camera system and illumination of the light source could not be optimized.